A new circular waveguide loaded with two T-shaped septa and a new triple ridge loaded trough rectangular waveguide are proposed and theoretically analyzed using the Finite Element Method. Numerical results are presented demonstrating that these structures offer a significant increase in both fundamental mode cutoff wavelength and bandwidth when compared to various unloaded and loaded waveguides.

A new ridge trough rectangular waveguide loaded with a horizontal “cross” ridge is proposed and analyzed using the finite‐element method. Analysis predicts a dramatic increase in the fundamental‐mode cutoff wavelength performance and high bandwidth. The waveguide is attractive for emerging microwave and millimeter‐wave applications requiring highly integrated, compact structures. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 20–23, 2001.